Chuck.



0. SJOSYTRAND.

GHUGK. A APPLICATION FILED JUNE 30, 1911.

Patented Dee.26, 1911.

2 SHEETS-SHEET 1.

' G. SJOSTRAND.

CHUCKr APPLIoA'rIoH FILED JUNE so, 1an.

1,012,781. Patentednmzawu 2 SUERTE-SHEET 2.

runnin-nml v yTo. my Conc-rai t.

Be itknown that I,CH.\RLES jcHAitLss'JosrRANnpF sir, PAUL, MINNESOTA.

SJosTnANn, a citizen of the United States, residing .at St. ll Paul, in the county -of- Ramsey and: State of Minnesota, have invented certain `new and -usefuli 'Improvements .in Chucks, of which the following is a specification.

Myinvent-ion 4relates to improvements iii to 'provide improved means for. securing the drill 1n the chuck, and consists in the features of-.constructiongand' combination here drill chucks, its `object being particularly inafterl vdescribed and claimed.`

In vthe accompanying drawings forming part of -tliisspecication Figure 1 is a verl tical section vthrough the vmiddle of' the chuck; Fig. '2 ,is a plan..view'of the plate vforming partofthe chuck; Fig.'3 isa conventional rview illustrating the method .of fastening the drill,within the chuck; Fig. 4 is a.,sectionalv Vieubroken away through thechuckpnline m of Fig. 1; Fig.5 is a side elevation, b roken away, of .the lower end of ,the shank, portion-of the chuck; Fig. 6 is a. detail viewof a. spring support formingV part oEfInyv invention Fig. 7 isha view partly in .peispective and partly in vertical sectionv ofaroller housingwith the top and .bottom removed forming part of my chuck;

Figs. 8 and 9 .are perspective views -ot the top .and bottom of the housing; F ig. 10 is a perspectiveview of a .lockving. key forming part of my invention: Eig. 11 is a perspective view of thelroller housing partly broken away; Fig. l2 .isa perspective y,view of a guide which works in connection with .the bottom" plate shown in.. Fig. 9; Fig. 13 .is a perspective view showing the bottom side of the plate illustrated in Fig. 9: and Fig.

14 isa perspective view of a locking key which coperates with the4 plate shown in Fig. 13. y

As shown in the drawings the chuck comprises a shell A having at the bottom an inturned annular flange 2 upon which rests a plate 3. Upon this plate rests a roller housing B formed with a central trefoil like support- 4, the lobes of which are involutely curved so as to permit and cause the rollers 5, one of which is arranged within each of the three lobes, to move inwardly toward the center. The rollers are held within the housing by means of top and bottom plates 6 and 7, respectively, which are screwed to the upper and lower ends of the housing, as shown in Fig. 3.

fcHUcx;

'Specication'of L'ettersvPat'efnt. t l Y -Patenfeldz-Dcc. 26, 1 Application medaglie 30,1911, serial no. f'c 3s,2i7k i The"topllpla-tel.isliforined `with.-- three Y volutely c urvedbpcningsf 8, through which the upper spindles 9. the rollers pass,= and in ywhich they work. #The bottom ,.pla te, Tis alsoformed with three similar and. registering openings 10, but the innen endsofthese opcningsmerge into a central hole adapted to receive the shank fof a drill l1. The lower spindles of the rollers pass through. andzwork within, these openings 10. l

The plate 3 is formed with a l lcentral l l opening 12rto receive the shank of the drill,

l17 upon the undersidecof thefl'ilate' ings20 'offset from the center and register: ing with the grooves '13`in the :plately The upper spindles 9 df 'the` rollers project through these holes, andA the plate,v 19 v.fits `down'ag'ainst the top ofthe housing'. the rim of the yplate 19 are t\vo (.ipposit ely arranged notches 20 adapted to receive a key 21, which also extends rthrough a long notch 22 in the reduced end 18 ofthe housmg: l l

Vlllien theV upper 'and lower plates 'Gand 7 of the housing havejbeen screwed into place l over the rollers. the housing is. placed upon the plate 3 within the shell A. Upon 'the threaded upper end of the'housingf is then screwed a cap 23. having a horizontal slot through which the key 21'- projects and 'y "4 works. As will be seen from .Fig. gl" the shell A is forinedwith a. vertical key way 24, which permits the key to be inserted into theshell, but which will cause the key to be turned with the shell. when the latter is turned. The cap 23 is madeintegral with an upwardly extending shank 25 which is intended to be made fast in the drill machine. At the upper end of the shell is a head 26 which is screwed down fast upon a washer 27 in which the shank 25 turns, the shell and head being held in rotatable engageinent by means of split rinr 28. The rollers are held in normal position within the housing by means of a spring 30 secured at one end to the v'shell A by means ofthe spring supporting device 31 and at the other end to the cap 23 of the housing.

It Will be seen that the shell A is normally held by the 'spring 30 in position where the rollers will stand clustered together at the center at the inner ends of the trefoil lobes. When the drill is to be inserted into the chuck the'shell A is turned by hand against the tension ofthe spring 30. As the shell turns it will carry with it the key 21, which will turn the plate 19 through which the upper spindles 9 of the rollers pass. When this plate is turned it .will force the rollers away from each other 'to the outward limit of their travel in the involutely curved` openings 8 and lobes 4t. The shank of the drill is then inserted into the hole 12 in the plates 3 and the registering opening 10 in the bottom plate 7 of the housing. The shell A is then released and is carried back by the spring 30 into its normal position. As Iit is thrown back it will carry with it the key 21 and the plate 19, thereby causing the rollersl to move inwardly together against the drill chuck 4so as to hold it firmly. The plates 14 which work in the grooves 13 will move freely with the roller-sand guide the travel of their lower spindles, so as to hold therollers always in parallelism. Thus by this apparatus, when a drill is to be inserted it is only necessary to ,turn the housing against the spring, in sert the drill, and release the housing. This will bring the rollers together into gripping position. The bottom plate 3 is held against turning by means of a key 32 which fits in aslot 33 in the underside of the plate 3 and projects into a notch`34 in the inwardly extending flange 2 of the chuck.

I claim as my invention:l

l. In a chuck of the class described, the combination of a shank, a shell rotatable thereon, a spring connecting said shank and shell, a housing within said shell, a plurality ofrollers journaled in said housing, a plate formed with inwardly directed slots receiving the adjacent ends of said rollers, means actuated by said shell for rotating 'said plate to draw the adjacent ends ofthe rollers inwardly for the purpose set forth.

2. In a drill chuck of the class described,

tively, means actuated by said-shell as it is rotated to force said rollers inwardly for the purpose set forth.

3. In a drill chuck of the class described,'

the combination with a shank, a shell rotatable thereon, a spring connection between said shank and shell, a housing within said shell, a plate rotatably mounted upon the end of said housingl and formed with inwardly curved slotted openings, a plate secured at the opposite end of said housing and .carrying inwardly slidable guides, a plurality of rollers supported at opposite ends in said slots and guides respectively, and means comprising a rotatable plate having inwardly directed straight slots receiving the adjacent ends of said rollers, said plate being operatively connected with the shell to force said rollers inwardly as the same is rotated upon the shank.

4:. In a drill chuck of the class described, the combination with a shell rotatable thereon, a spring connection between said shank and shell, a housing` within said shell, a plate rotatably mounted upon the end of said housing and formed with inwardly curved slotted openings, a plate secured at the opposite end of said housing and carrying inwardly slidable guides, a plurality of rollers supported at opposite ends in said slots and guides respectively, and means for forcing said rollers inwardly comprising, a plate formed with inwardly extendlng straight slots for` receiving the adjacent ends of said rollers and a key locking together said plate and shell.

In testimony whereof I affix mysignature in presence of two witnesses.

^ CHARLES SJOSTRAND. Witnesses:

Wirren!) OLSON, OLor. OLSON. 

